US3779886A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control and indicator circuits for coulometric titrators
Assignee: TDK Micronas GmbH
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Filing: 1972-05-17
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Granted: 1973-12-18
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Expires: 1992-05-17
Abstract
Abstract A control circuit for a coulometric titrator having a recording voltmeter connected therein. The circuit utilizes two transistors of opposite conductivity types between which a low pass filter is connected. An emitter bias resistor is employed with one transistor. A zener diode and a resistor provides quiescent bias for the other transistor. The one transistor is provided with a base bias that is adjusted through the use of a potentiometer to cause both transistors to operate slightly above cut-off when the monitored fluid concentration is zero. The zener, the filter and the one transistor emitter resistor all improve the signal-tonoise ratio at the voltmeter without reducing the voltmeter dynamic response or accuracy of indication. The extraordinary range of the instrument is, for this reason, down to two parts per billion.
Inventors
- 👤 Moen A Dean
- 👤 J Robison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:51
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/42; G01N27/423
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
14 words
The invention as defined in claim 1, wherein said first means includes a resistor.
Claim 2
Dependent Claim
41 words
The invention as defined in claim 2, wherein said fourth means includes a resistor and a zener diode connected in series, said potentiometer being set so that both of said transistors are above cut-off with a monitored fluid concentration of zero.
Claim 3
Dependent Claim
156 words
The invention as defined in claim 3, wherein a capacitor is connected from said first transistor base to said first transistor collector, said fifth means including a resistor, said filter including an auxiliary resistor, and a capacitor connected from said first and second ends thereof, respectively, to said minus junction, said first and second ends of said auxiliary resistor being connected to one end of said fifth means resistor and said second transistor base, respectively, said second means including a resistor, said indicator circuit including a recording voltmeter and first, second and third resistors connected in series in that order from said second transistor collector to said reference electrode, a capacitor connected between the junction of said second and third resistors to said second transistor collector, another capacitor connected from the junction of said first and second resistors to said second transistor collector, and a resistor connected from said second transistor collector to said reference electrode.
Claim 4
Dependent Claim
41 words
The invention as defined in claim 1, wherein said fourth means includes a resistor and a zener diode connected in series, said potentiometer being set so that both of said transistors are above cut-off with a monitored fluid concentration of zero.
Claim 5
Dependent Claim
198 words
A coulometric titrator comprising: an electrolytic cell including generator, reference and sensor electrodes; a D.C. source of potential having plus and minus output junctions, said generator electrode being connected with said plus junction; first and second transistors each having a collector, an emitter and a base, said first transistor being of a PNP conductivity type, said second transistor being of an NPN conductivity type; first means connecting said plus junction to said first transistor emitter; a potentiometer having a winding and a wiper, said winding being connected between said plus and minus junctions; second means connecting said wiper to said first transistor base, said first transistor base also being connected with said sensor electrode; third and fourth means connected in parallel between said second transistor base and said minus junction; fifth means connecting said first transistor collector to said third means; and an indicator circuit connected between said second transistor collector and said reference electrode, said second transistor emitter being connected to said minus junction, said fourth means including a resistor and a zener diode connected in series, said potentiometer being set so that both of said transistors are above cut-off with a monitored fluid concentration of zero.
Claim 6
Dependent Claim
14 words
The invention as defined in claim 6, wherein said first means includes a resistor.
Claim 7
Dependent Claim
171 words
A coulometric titrator comprising: an electrolytic cell including generator, reference and sensor electrodes; a D.C. source of potential having plus and minus output junctions, said generator electrode being connected with said plus junction; first and second transistors each having a collector, an emitter and a base, said first transistor being of a PNP conductivity type, said second transistor being of an NPN conductivity type; first means connecting said plus junction to said first transistor emitter; a potentiometer having a winding and a wiper, said winding being connected between said plus and minus junctions; second means connecting said wiper to said first transistor base, said first transistor base also being connected with said sensor electrode, third and fourth means connected in parallel between said second transistor bAse and said minus junction; fifth means connecting said first transistor collector to said third means; and an indicator circuit connected between said second transistor collector and said reference electrode, said second transistor emitter being connected to said minus junction, said first means including a resistor.
References Cited (Backward Citations)
US3448031A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |